Photoluminescence properties and energy transfer investigations of Gd3+ and Sm3+ co-doped ZnO–BaO–TeO2 glasses for solid state laser application

Effect of Al2O3/Ga2O3 ratio on the structure and luminescence properties of Sm3+ doped SrO-Nb2O5-Al2O3-Ga2O3-SiO2 glasses

The Sm3+ doped SrO-Nb2O5-Al2O3-Ga2O3-SiO2 glasses in this work were prepared using the conventional melt quenching method. The effects of Al2O3/Ga2O3 ratio on the structure and orange light emission properties were studied by XRD, Raman spectroscopy, spectrophotometer and J-O theory, respectively. With the increase of Al2O3 content, the absorption coefficient of the glass sample gradually increases, which might be attributed to an increase in non-bridged oxygen bonds caused by a change in the glass network structure. Under 403 nm excitation, the emission spectra show clear peaks at 602 nm and 649 nm, representing the 4G5/2 → 6H7/2, and 4G5/2 → 6H9/2 transitions, respectively. When the Al2O3/Ga2O3 ratio is 0.25, the sample luminescence intensity is the highest, and the emission cross section of A2 glass sample is 4.34 × 10-22 cm2. The CIE color coordinates, color purity, and color temperature values of all samples were determined, and they were all located in the orange-red light region. The experiments results reveal that the prepared silica-aluminum-gallium glasses has a potential application prospect in orange-red LEDs, solid state lasers and other fields.

Comprehensive analysis of color-tunable luminescence of Sm3+/Eu3+ ions co-incorporated tellurite glasses for optical device applications

The effects of co-doping Eu3+ ions in Sm3+ embedded WO3-Na2O-MgO-TeO2 glasses have been explored. The XRD spectrum determines the amorphous nature of the prepared sample. The UV-Visible spectra show that the dominant absorption bands occur at 7F0 → 5L6 (393 nm) and 7F0 → 5D2 (463 nm) for Eu3+ doped glass and the dominant absorption band for Sm3+ ions doped glass arises at 6H5/2 → 6P3/2 (402 nm). The energy transfer from Sm3+ → Eu3+ (4G5/2 → 5D0) upon excitation at 402 nm has been verified using the theory proposed by Dexter and Forster. The Inokuti-Hirayama model suggests that the possible energy transfer is dipole-dipole in nature which happens in Sm3+/Eu3+ co-doped glasses. As the energy levels 4I13/2 of Sm3+ ions and 5D2 of Eu3+ ions are very close, the luminescence transition due to 4G5/2 → 6H5/2 occurs upon excitation at 463 nm in co-doped glasses. The CIE1931 chromaticity coordinates illustrate that the present co-doped glasses have a range of emission from orange to red. The chroma and hue of the emitted colours of the present co-doped glasses are also computed using CIELab and it shows a linear change from orange to red with the increasing Eu3+ ion concentration in the present co-doped glasses. The obtained results show that these glasses have potential to find applications in various fields like solar cells, solid state lighting, display devices etc.